Abstract
Concentrations of P, Fe, Zn, Cu, Mn, Cr, Pb, Ni, Ag, Cd, As, Co, Hg, and Se in the influent and effluent of 25 sewage treatment systems in different metropolitan areas of the United States were measured. Attenuation of the concentrations of these elements in primary effluents, secondary effluents, and discharges, relative to raw sewage, was calculated. These calculations indicate that the best removal occurs for Pb, followed by Zn, Fe, Cr, Cd, Cu, P, Ag, Ni, Mn, and Co.
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